For the sofrito, place the onions, tomatoes and garlic into a non reactive pan and cover halfway with the olive oil. Sprinkle the saffron threads on top and place over a medium flame. Cook until very soft and well combined with no color or caramelization.
Place a paella pan on a medium flame with a touch of extra virgin olive oil.
Saute the chorizo and the peppers briefly to just brown the sausage a touch.
Add the peas, sofrito, chicken, scallops, rice and paprikas and mix in the pan until well combined.
Add the saffron broth, it should just barely cover the rice. Bring the pan to a boil and cover with aluminum foil or a lid.
Place the paella pan into a 375F oven for about half an hour or until the rice is ¾ of the way cooked.
With about 10 minutes of cooking time left add the shrimp, mussels and clams to the rice and arrange it attractively. Re-cover the pan and cook another 10 minutes or until the rice is cooked and the seafood as well.